1. Field of the Invention
The present invention relates to a pair of pruning shears, and more particularly to a pair of pruning shears having a lock device to securely hold the shears in a pushed position.
2. Description of Related Art
With reference to FIG. 6, a pair of conventional pruning shears in accordance with the prior art comprises two bodies (30,32) pivotally mounted together with a pivot. Each body (30,32) has a cutting end (302,322) formed on one end thereof and a handle (304,324) on another end. A spring (34) is connected between the handles (304,324) of the bodies (30,32) to provide a biasing force to push the handles (304,324) far away from each other. Therefore, the cutting ends (302,322) of the bodies (30,32) will keep in an open condition by the biasing force of the spring (34). However, a user, especially a child, is easily cut by the open cutting ends (302,322) of the bodies (30,32) when he or she holds the pruning shears in play. Consequently, a lock device is always disposed between the bodies (30,32) to keep the pruning shears in a closed condition when the shears are not in use.
The conventional lock device comprises a block (36) slidably mounted on the handle (304) of one of the bodies (30) and a recess (326) defined in the cutting end (322) of the other one of the bodies (32). When the bodies (30,32) are pushed toward to each other, the recess (326) will face the block (36). The bodies (30,32) will be locked as the block (36) is pushed to slide along the handle (304) and engage with the recess (326). With such a lock device, the pruning shears can be held in the closed condition so as to avoid a person being cut by the cutting ends (302,322).
However, because no positioning structure is applied to the block (36), the engagement between the block (36) and recess (306) is not enough. In particular, there is always a gap defined between the block (36) and the body (30) to reduce the friction therebetween and this will further decrease the engaging strength between the block (36) and the recess (326) furthermore, the block (36) easily escapes from the recess (326) as the pruning shears bumps with another object or drops to the ground.
To overcome the shortcomings, the present invention tends to provide a pair of pruning shears with an improved lock device to mitigate or obviate the aforementioned problems.
The main objective of the invention is to provide a pair of pruning shears with a lock device to securely hold the shears in a closed position. The pruning shears comprises two bodies pivotally mounted together with a pivot, a spring connected between the bodies and a lock device arranged near the pivot. The lock device comprises a step hole, a locking hole, a latch post, a biasing member and a knob. The step hole is defined in one of the bodies near the pivot, and the locking hole is defined in the other body to align with the step hole when the bodies are pushed together. The latch post is moveably mounted in the step hole. The biasing member is received in the step hole to support the latch post. The knob is rotatably mounted on the body with the step hole. The knob has a bottom abutting the latch post and a cavity defined in the bottom of the knob to face the latch post. The latch post can be pushed to engage with the locking hole by the bottom of the knob. This can provide a securely positioning effect to the latch post to avoid the post escaping from the locking hole as the pruning shears bump with another object, fall, etc.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.